Fish as Pets | Aquarium, Pond News, Editorials, Reviews

AQUARIUM PLANARIA OR ACTUALLY DETRITUS WORMS?

Updated 9/18/23

Detritus Worms (to the left)

This post was/is inspired by the many questions I have read or been asked from readers of my articles, conversations, or forum members (Everything Aquatic in particular) as to Planaria, which most of the time have been mis-identified via "cut and paste" Internet articles found on websites such as eHow, then repeated all over the Internet in the many anecdotal forums, despite the fact there are many true experts with decades of experience out there that could be consulted.
Referenced aquarium/pond keeping forum:
Everything Aquatic Aquarium Forum

WHAT ARE THE FACTS & THE IMPORTANCE OF THESE FACTS AS IT RELATES TO HOW TO DEAL WITH THESE WORMS:

The facts are that 85-90% of the time these thin as a hair and white worms that persons sometimes even see swimming though the water in the middle of the aquarium are instead Detritus worms which are an "Annelid" not even closely related to Planaria (which are flat worms).
As well many of these sites, even when correctly identifying these worms, are incorrectly stating their cause such as over feeding which is true for Detritus worms, but generally not Planaria!!!

This mis-identification and confusing of treatments did not even exist (that I knew of) prior to the Internet. However with the plethora of persons writing articles with little or no expertise on the subject in an attempt to boost Internet exposure for their client's web site, this problem began.
Then after Google algorithm changes that weighted so called authority sites and social media, these bad articles rose to the top. Of late, now we have circular internet and social media forums now spreading full or mixed truths about Planaria & Detritus worms, their causes, what they feed on, and treatment. Unfortunately it seems that aquascaping forums of late are leading the way here with mixed information.

As an example, I had a client looking for help. Unfortunately she went to a fish forum and bad Internet articles (I will cite these later in this article), the result of one incorrect identification resulted in her killing off many of her fish.
She followed the advice given to her to treat with Levamisol, this was based on a forum members suggestion after reading one of the many incorrect Internet articles that the search engines love to serve up.

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I have also read many "horror" stories while browsing through forum posts whereby they were initially convinced they had a problem with planaria in their tanks after being told by many other fish keepers, aquariums stores or by searching on the internet.

This has resulted in snake oil products for non existent problems to emerge such as "No Planaria" (sold by "Green Leaf Aquariums" which Google's now terrible algorithm changes have brought to prominence).

What was the result? This resulted in a massive die off of the Detritus worms that quickly depleted the water of oxygen (which was already somewhat depleted due to the causes of the worm population explosion), as well as a sudden spike in ammonia, thus taking out the fish as well.

In other instances I have read many forum posts where the person posting were initially adding products such as "No-Planaria" purchased from businesses more than willing to take their money for an imaginary problem. This often led to double doses of these meds resulting is stressed fish since they are not best remedy for what these worms really are; DETRITUS WORMS.

The facts are, while Planaria MAY be dangerous to fish Detritus Worms are not and a population surge indicates other issues that are best addressed without medication use, NOT THE USE OF LEVAMISOL, "NO-PLANARIA", OR OTHER TREATMENT!!!
Detritus worms are generally only dangerous when oxygen levels are low with high bio loads where they compete with fish for oxygen. Some persons have claimed these worms have attacked their fish or shrimp, but in every case I have been sent pictures or made a house call, the worms were Planaria or more often indeed Detritus Worms, but were simply doing what a decomposter (detritivore) does; scavenge a dead or nearly dead fish or shrimp!!

The point is, the problem with this confusion of these two very different worms IS IMPORTANT since infestations of each of these different worms has very different implications for your aquarium, So Please Read On!

What are Detritus Worms?

These Detritus Worms are normally not a problem and often go un-noticed aiding in breakdown of wastes while living in the gravel or filter media (such as sponges, bio balls, etc.). In fact these worms are generally beneficial in aiding in larger waste breakdown, as well these worms can even be a healthy food source for fish.
However when the population explodes these worms often leave the gravel and cling to the sides, usually close to the surface as oxygen depletion due to the cumulative effects of increased organic mulm, cloudy water and simply too many Detritus worms drive them from the oxygen poor gravel.

The population explodes generally due to high amounts of decomposing organic mulm (often resulting in cloudy water, pH drops, etc.), which is often an indicator of a tank with one or usually more of these problems:

Poor filtration
Poor cleaning practices
Reference: Aquarium Cleaning, methods, reasons, more
Too high of a bio load (number of fish, etc.)
Poor bio filtration or simply poor bio filters (Sponge Filters, or Fluidized Sand Bed Filters are the most efficient bio filters)
Product reference links: PREMIUM Aquarium Sponge Filters; Model #3 & Fluidized Sand Bed Filter; Highest bio capacity aquarium filters
Poor Redox Balance
Reference: The Aquarium Redox Balance and its importance to good fish health
Poor feeding practices (not always over feeding, sometimes simply feeding foods that do not digest well) and other reasons as well.
Reference: Proper Fish Nutrition

Treatment/Removal of Detritus Worms

Generally just improving the above noted factors will lower your detritus worm numbers to where they will again go un-noticed and be at much safer numbers for your aquariums bio load capacity.
Complete removal is not necessary and generally not even recommended since these are excellent decomposters.

Generally when you see these worms emerging is when the oxygen levels are depleted in the substrate and these worms are seeking oxygen, so chemical treatment as generally for Planaria will further deplete oxygen and thus further deplete oxygen, often killing fish too.
I should note that often during power failures, these worms will then emerge seeking oxygen even when your tank has an otherwise well managed bio load.

For further information about the subject of worms, please see my Aquarium Answers Article:
* “Aquarium Answers; Trematodes and Nematodes in Aquariums” which includes information about these worms near the bottom of the article.

Detritus Worms Video

Planaria (below)

As for Planaria versus Detritus Worms, no one has bothered to check with any zoological, biology or similar research site.

In the case of Detritus Worms (being identified as Planaria), I checked several sources to confirm what was a baffling amount of poor information in aquatic sites, yet all the biology sites confirmed the rather obvious difference between Planaria and Oligochaetes Worms (the family of worms that compost in water that includes tubiflex, naidid, and similar worms).

Planaria are tiny flatworms that live in freshwater and marine environments, and on plants throughout the globe.
Planaria we do occasionally observe in aquariums are more naturally found fresh water ponds or temperate lakes, and are carnivores or scavengers (scavengers. in the sense of a vulture, most definitely NOT a decomposter)!
Another key point about Planaria is these flatworms are generally only seen in VERY small numbers of individuals, unlike Detritus Worms which can number in the 100s or more.

Further Planaria Information:
The pharynx (the passageway leading from the oral cavity in the head to the esophagus) can be protruded from the mouth which is in the middle of the ventral side of the animal. The diet consists of such foods as insect larvae, small crustaceans, and other small living and dead animals, NOT decomposing matter as Detritus Worms do.

Planarias reproduce asexually and sexually; individuals have both testes and ovaries.
A single one can be cut into hundreds of pieces and each will grow back into a whole planaria —a remarkable feat of regenerative capacities.

The implication of a true Planaria infestation is VERY different from the much more common Detritus worm infestation, which is why this correct identification is so important.
Planaria can harm some fry, fish eggs, or even occasionally resting or weak fish, and are generally not an indicator of a dirty aquarium as is the common myth.

Planaria is normally transferred into an aquarium from live plants normally grown in a pond. Generally ponds have more incidence of Planaria.

Where as Detritus Worms are primarily decomposters (detritivores) that cause little harm unless their population explodes which then they compete for oxygen with fish and are an indicator of poor tank conditions in general. When Detritus worms are out from the gravel crawling on the glass, etc, this is a sign of a “dirty aquarium” with implications of high amounts of mulm and lower dissolved oxygen as noted earlier.
Under NORMAL conditions, Detritus worms are no more harmful to you or your aquarium inhabitants than an earthworm is to you and your garden!

Removal (Treatment) of Planaria, which unlike Detritus worms SHOULD be totally eliminated

There are several remedies that can rid a tank of Planaria, which the positive with treatment elimination is since Planaria are generally only found in very small numbers, the die off not cause a problem decreased oxygen or toxins released (unlike snails, detritus worms, etc.).

Here are a few:

*Clout; this is one of the most effective treatment blends which contains:
4-[p-(dimethylamino)-)O-Phenylbenzylidene]-2,5-cyclohexadien-1-xylidene dimethylammonium chloride; dimethyl (2,2,2-trichloro-1-hydroxy-ehtel) phosphonate; 1,2-dimmethyl-5 nitromidazole and inert ingredients as non toxic binders.
A negative of this treatment is it cannot be used with Piranhas, Metynnis species, scalelesss fish, bottom feeders, Marine Sharks, or Lion Fish.
Product Reference: Aquarium Products Clout Parasite Treatment

*Trichlorfon (Dylox); found in AAP Dyacide. This is one of the most pure products for treatment of most all external multi cell parasites including Planaria, Flukes, & Anchor Worms.
With the demise of Clout, "AAP Dyacide" is now the only truly effective treatment now available.
Product Reference: AAP Dyacide (Pharmaceutical Grade Dylox)

Further Reading: Aquarium Medications Part 3; Trichlorfon

*General Cure; Not as strong, but still often effective and less harsh on delicate fish. General Cure contains Metronidazole & Praziquantel
Product Reference: API Mars Fish Care General Cure Parasite Treatment

*Levamisol

*Copper at .25 ppm MAY be effective for Planaria

*Be wary of many wormers not normally meant for aquatic use, that may work, but dosing can be tricky and over dosing has happened.

*Often ParaGuard or Flubenol is recommended, but using it is only mildly to moderately effective on Detritus Worms and rarely is effective for true planaria

Other references:

*https://www.exploratorium.edu/
*https://www.baruch.cuny.edu/

Aquarium Parasites, Nematodes, Trematodes, Planaria, more

SUMMARY

What is so disgusting about the confusion of Detritus Worms with Planaria is the fact that this confusion did not exist prior to the Internet.
Quite frankly these two 'animals' have about as much in common as an opossum and elephant, so the fact that so many are this gullible and search engines such as Google in particular are this bad SPEAKS VOLUMES!!

What has happened is apparently someone posted this extreme mistake and others then being lazy, simply re-posted it over and over with terrible spam websites such as about.com then also spamming it further.
Correct information used to "rise to the top" of Google searches for "Aquarium Planaria", but with all this spam with the same exact incorrect information, the newer Google algorithms have labeled the truth as spam and spam as truth..... so much for trusting a your "Googling"!!!

As well, with Facebook forums such as "Fish Tank Enablers" run by anecdotal disrespectful moderators with no understanding of scientific method or respect for mentoring, myths such as this further get pushed along.
Examples of other myths:
Common Aquarium Keeping Myths

Another purpose of this post/article is to bring attention to readers (who keep and maintain aquariums and ponds) to be careful about believing everything written, blogged, etc. here on the internet when it comes from some aquatic sites.

What I have noticed being in the maintenance and also research side of this business is that someone will write and anecdotal article with no research behind it and then others will pick this up and run with this poor information. This is especially common with information spam sites like about.com which were created purely for advertising revenue.

INTERNET MISINFORMATION ABOUT PLANARIA:

Here are a couple of "Gems" from eHow.coms misinformation campaign:
Quotes: "Planaria thrive in freshwater aquariums that are not properly cleaned or contain lots of excess food at the bottom".
AND: "Many freshwater fish enjoy eating these worms. Although the worms are not harmful to the fish, the conditions in which they thrive can be fatal. Planaria can even get into the gills of fish, causing irritation. While filling your tank with Planaria-eating fish can take care of a few worms, the overall conditions that allow Planaria to grow must be treated so no harm will come to the fish".

FACT: There are FEW fish that will eat true Planaria!
There are NO conditions that cause a Planaria outbreak, only Detritus Worms, sorry eHow, Planaria are carnivores!

This whole article at eHow revolves around Detritus Worms even though the heading is about Planaria.

The other part of this confusion by these “cut and paste” sites/articles is even when correctly identified, Planaria are still attributed to the same water conditions that cause a Detritus Worm population “explosion” which is simply not true and can lead an aquarium keeper to address non existent problem if they believe this misinformation from sites such as Aquarium Wiki or planetinverts.com.

Planetinverts.com in particular is a website that correctly identifies Planaria, but then goes on to describe the remedy for a Detritus worm out break. The danger here is if you truly do have a Planaria infestation, just lowering bio load, feeding, etc., will NOT work, so this web site is placing the aquarium keepers fish, shrimp, etc in danger with such poor information.

Summary of Misinformation provided by Google Search Results!

Here are just a few of the websites with misinformation on this subject & more

*www.onedersave.com/ (This is simply a "Cut & Paste" site with no research!!)
*www.fishdeals.com/fish_diseases/planaria_white_worms/
*www.aquariumfish.net/information/having_trouble_p2.htm
*www.theaquariumwiki.com/Planaria
*www.aquaticplantcentral.com/forumapc/general-aquarium-plants-discussions/67061-planaria-surprise.html
*www.planetinverts.com
*Yahoo Answers
*Aquarium Wiki
*Aquarium Fish.Net
*Fish Deals
*About.com
*FishLore
*www.cuteness.com/article/aquarium-fish-eat-planaria

As well many persons often think that Wiki has it correct, yet they are dead wrong and even misidentify the type of worm these are calling them a nematode as well as stating they "feed on dead and decaying organic materials"
*Flatworms

In Closing as to Aquarium Keeping Misinformation in General; Besides experience I have gained in the maintenance business, research, seminars, I still do not assume that what I know is correct and re-research often and I often research out side the aquarium industry in areas such as microbiology, the lighting industry, medical, and other research and outside industry sites.

There are several more subjects with vast amounts of poor information, such as nitrifying bacteria, what they are, can they be packaged and whether or not antibiotics will kill them.
The fact here is that true nitrifying bacteria belong to the family Nitrobacteraceae and REQUIRE oxygen and are gram positive bacteria that react to gram positive treatments while most pathogenic bacteria in aquatics (freshwater and even more so in saltwater) are pure gram negative bacteria. This means that these bacteria can live short periods at room temperature in a liquid.
Reference: Aquarium Nitrogen Cycle; Nitrification & Nitrobacteraceae Bacterium

The other poor information aspect to this is many sites, forums, blogs that state that most all medications will kill your nitrifying bacteria, while this is certainly true of Erythromycin or Tetracycline which are gram positive this is NOT true of Kanamycin or Nitrofurazone which are primarily gram negative (these antibiotics do have some gram positive abilities as well and so overuse can and will harm nitrifying bacteria).
References:
Aquarium Medications 2; Erythromycin, Tetracycline, Kanamycin, & Nitrofurazone
Aquarium Medications 1; Gram Negative & Positive Bacteria

Finally it is often amazing how many persons will recommend a primarily gram positive antibiotics such as Penicillin or Tetracycline for gram negative disease such as Aeromonas, Septicemia or Columnaris.
References:
Aeromonas, Septicemia
Columnaris

Readers might be interested in this article also from "Fish as Pets Aquatic News Articles" dealing with misinformation about aquarium lighting:
PUR or RQE, YouTube Video Fail- Guide to lighting a planted tank

Recommended Aquatic Sites

One of the most effective medication for the treatment of Columnaris in an aquarium when used as part of the four step program of Columnaris treatment.
A more synergistic combination than purchasing Kanamycin & Nitrofurazone separately.

AAP Yellow Powder; For Columnaris & Aeromonas The MOST effective treatment when combined with Kanamycin

YouTube; How to: 4 Steps Columnaris Treatment Fish Bacterial Infection

This video goes over the basics of the full four step plan of properly treating Columnaris in aquarium fish and is a compliment to a FULL reading of this article.

The article below is a MUST READ for anyone interested in moving from basic aquarium keeping to more advanced aquarium keeping, including better Redox Balance:

Ultraviolet Sterilization, Advanced Aquarium Keeping